Nilfisk-Advance Convertamatic 24 Service Manual

Also see for BA 625: Instructions for use Instructions for use

Contents

Nilfisk-Advance Convertamatic 24 Service Manual Manual pdf 41 page image

FORM NO. 56043098 - Convertamatic ™ 24, 26, 28, 32 / BA 625, 725, 825 - 39WHEEL DRIVE SYSTEMGENERAL FUNCTIONAL OVERVIEWSee Figures 1 and 2. A 300 watt (.4 HP) permanent magnet (24V) motor transaxle (M1) is used for the wheel drive on all machines. A Curtis PMC solid state speedcontroller (A2) regulates the variable speed and Fwd/Rev wheel drive motor functions. Location of the controller is in the rear handle housing electrical compartment(accessible by removing the 4 screws securing the rear electrical panel). The potentiometer R1 mounted inside the drive paddle inputs to the A2 controller themachine operator’s throttle (variable speed) and direction demands. A second pot R2 (knob adjusted) is located on the outside of the paddle cover and controls themachine’s maximum transport and scrub speeds.Drive Motor System FunctionSee Figures 2 and 3. With the key switch S3 closed the Brn wire inputs 24V to the A2 speed controller (Pin 5-KSI) to make its internal control circuits operational(powering it up). The F3 circuit breaker (30 Amp) supplies the positive load circuit voltage input to the B+ controller terminal (Wht/Yel wire). The black wire from thebattery negative standoff supplies the (NEG.) input to the B- controller terminal.Moving the 5K Ohm R1 pot off its centered balanced neutral setting of approximately 2500 Ohms, activates the operator input to the speed control. Forward orReverse movement of the drive paddle rotates the pot shaft and the pot’s variable resistance values are changed, which generates the internal voltage signals(0-5Volts) needed for the controller’s output operation. These control board voltage input signals are what energizes the Fwd and Rev directional relays, which thenselects the motor polarity and fi nal voltage level outputs at the M1 & M2 terminals.When the operator turns the R2 speed limit Pot from min. to max. (CW) this causes an input resistance relationship change between the pot high (+) and wiperterminals (high to low Ohms) thus increasing the maximum wheel motor operating speed range. Turning the knob (CCW) increases the resistance and the motorspeed range is reduced.FIGURE 1